Users are increasingly performing tasks using remote computing resources, which may be offered through a shared-resource environment. This has many advantages, as users do not have to purchase and maintain dedicated hardware and software, and instead can pay for only those resources that are utilized at any given time, where those resources typically will be managed by a resource provider. Users can perform tasks such as storing data or executing applications using various types of resources offered by the resource provider. In some environments resources can be allocated on a task-specific basis. For security reasons, a separate resource instance can be initialized for each such task. The need to initialize a new instance for each task can be very resource intensive, however, and can introduce an amount of latency in the processing of each task.